From its inception in 1922 the BBC’s programmes were radiated from a number of low-power transmitters located in the centre of the principal towns and cities across the UK. To provide coverage to country areas remote from these transmitters a more powerful long-wave transmitter was inaugurated at Daventry in 1925. As broadcasting gained in popularity during the 1920s many low-power repeater stations were opened in various towns to fill in the gaps in the medium-wave coverage. The BBC then adopted a new plan to provide national coverage at medium waves with a smaller number of high-power transmitters located away from the cities. This was called the ‘Regional Scheme’ and the first of these to open was at Brookmans Park, Hertfordshire, in 1929, serving London and much of the south-east. The transmitters at Brookmans Park were designed by Marconi’s Wireless Telegraph Co Ltd and became the standard for all the Regional stations opened in the next few years.

There were two transmitters at Brookmans Park. The first, which began working in October 1929, was the London Regional transmitter and replaced both the London 2LO transmitter at Selfridge’s, Oxford Street, and its back-up at Marconi House. The second, for the new National programme, began working in March 1930. Both Brookmans Park transmitters remained in use (or available for use) until 1979, when they were scrapped. The technical manual was prepared for staff use at Brookmans Park at the time the first transmitter was installed. It provides considerable detail on the circuits of the transmitters and usefully supplements the description of the Brookmans Park station contained in the paper by P Eckersley and N Ashbridge which was published in the Journal of the Institution of Electrical Engineers, Vol 68, 1930.